JP2008158299A - Fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device, etc. capable of increasing efficiency of cooling paper. <P>SOLUTION: A fixing belt 13 is wound and stretched between a heating roll 11 and a cylindrical peeling roll 12 and heated by the heating roll 11. A pressure belt 15 is pressed against the fixing belt 13 by a pressure pad 16 and a soft pad 21, so that a nip portion N is formed. A cooling device 14 for cooling the paper P after passing through the nip portion N is arranged between the heating roll 11 and the peeling roll 12, on the inner circumferential surface side of the fixing belt 13 and a paper guide 23 is arranged so as to face the cooling device 14, on the outer circumferential surface side of the fixing belt 13. The paper guide 23 is air-cooled. The paper P conveyed by the fixing belt 13 is cooled by the cooling device 14 and the paper guide 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fixing device and an image forming apparatus.

  Due to recent improvements such as digitalization and high definition, a color image forming apparatus can obtain high-quality images. Along with this improvement in image quality, attempts have been made to develop color image forming apparatuses using an electrophotographic system in the printing market and the photographic market. For example, Patent Document 1 discloses a technique for dealing with such an attempt. Patent Document 1 discloses an image forming apparatus including an image forming unit, a first fixing device, and a second fixing device. In this image forming apparatus, high-gloss image output is possible by performing primary fixing with the first fixing device and then secondary fixing with the second fixing device.

JP 2004-109905 A

  An object of the present invention is to provide a fixing device or the like that can increase the cooling efficiency of a sheet.

  For such a purpose, a fixing device to which the present invention is applied forms a nip portion by a fixing belt to which heat is applied and a pressure member pressed to the fixing belt, and a recording sheet passes through the nip portion. The toner image on the recording sheet is melted by the heat of the fixing belt and pressed against the recording sheet, and the toner is positioned on the inner peripheral surface side of the fixing belt. A first cooling unit that cools the image while the image is melt-pressed and adhered to the fixing belt while being attached to the fixing belt; and the fixing unit that is positioned on the outer peripheral surface side of the fixing belt. A second cooling unit for cooling the non-adhering side of the recording sheet attached to the belt, and a peeling unit for peeling the recording sheet cooled by the first cooling unit and the second cooling unit from the fixing belt. The Is Dressings.

  Here, a restricting portion that is disposed between the melt-bonded portion and the first cooling portion and / or the second cooling portion and further restricts heat transfer from the melt-bonded portion to the cooling portion is further provided. It can be characterized by including. The second cooling unit may include a recording sheet guide surface. Also, a heat exhaust unit that exhausts heat from the first cooling unit and the second cooling unit to the outside of the apparatus, and a connection that connects the first cooling unit and the second cooling unit to the heat exhaust unit And a portion.

  From another viewpoint, the fixing device to which the present invention is applied includes a heat source, a fixing belt that receives supply of heat from the heat source, a pressure member that is disposed so as to contact the fixing belt, and the fixing device. A pressure member for forming a nip portion through which a recording sheet is passed between the belt and the pressure member, and the fixing belt are wound around, and the recording sheet attached to the fixing belt is peeled off at the nip portion. A peeling member; a first cooling device for cooling the image surface of the recording sheet adhering to the fixing belt; and a second cooling device for cooling the non-image surface of the recording sheet adhering to the fixing belt. , Including.

  Here, it further includes a limiting unit that is disposed between the heat source and the first cooling device and / or the second cooling device and restricts heat transfer from the heat source to the cooling device. It can be. In addition, a heat exhaust unit that exhausts heat from the first cooling device and the second cooling device to the outside of the fixing device, and the first cooling device and the second cooling device are connected to the heat exhaust unit. And a connecting portion. Also, an exhaust heat unit that discharges heat from the first cooling device, the second cooling device, and the peeling member to the outside of the fixing device, the first cooling device, the second cooling device, and the peeling member. And a connection part that connects the heat exhaust part to the exhaust heat part.

  Further, from another point of view of the present invention, an image forming apparatus to which the present invention is applied includes a toner image forming unit that forms a toner image, and a toner image formed by the toner image forming unit is transferred onto a recording sheet. And a fixing unit that fixes the toner image transferred onto the recording sheet to the recording sheet. The fixing unit includes a fixing belt to which heat is applied and a pressure applied to the fixing belt. Forming a nip portion with the pressure member, and when the recording sheet passes through the nip portion, a melt pressure bonding portion that melts the toner image on the recording sheet by the heat of the fixing belt and press-bonds to the recording sheet; Located on the inner peripheral surface side of the fixing belt, the toner image is melted and pressure-bonded by the melt-bonding portion, and the recording sheet attached to the fixing belt is attached to the fixing belt. A first cooling unit to be rejected, a second cooling unit that is located on the outer peripheral surface side of the fixing belt and that cools the non-adhering side of the recording sheet attached to the fixing belt, the first cooling unit, And a peeling unit for peeling the recording sheet cooled by the second cooling unit from the fixing belt.

According to the first aspect, it is possible to improve the cooling efficiency of the paper as compared with the case where the present invention is not applied.
According to the second aspect, compared to the case where the present invention is not applied, it is possible to restrict unnecessary heat from being transmitted to a location to be cooled, and it is possible to reduce the size of the apparatus.
According to claim 3, it is possible to reduce the number of constituent members as compared to the case where the present invention is not applied.
According to the fourth aspect, compared with the case where the present invention is not applied, cooling can be performed even if the distance from the melt-bonding portion to the peeling portion is shortened, and high-quality image output is possible even if the size is further reduced. Become.
According to the fifth aspect, it is possible to increase the cooling efficiency of the paper as compared with the case where the present invention is not applied.
According to the sixth aspect, compared to the case where the present invention is not applied, it is possible to restrict unnecessary heat from being transmitted to a place to be cooled, and it is possible to reduce the size of the apparatus.
According to the seventh aspect, compared with the case where the present invention is not applied, cooling is possible even when the distance from the melt-bonding part to the peeling part is shortened, and high-quality image output is possible even if the size is further reduced. Become.
According to the eighth aspect, compared to the case where the present invention is not applied, cooling can be performed even if the distance from the melt-bonding portion to the peeling portion is further shortened, and high-quality image output is possible even if the size is further reduced. Become.
According to the ninth aspect, it is possible to improve the cooling efficiency of the paper as compared with the case where the present invention is not applied.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments showing an example of the present invention will be described below with reference to the accompanying drawings.
[First Embodiment]
FIG. 1 is a side sectional view showing a configuration of a fixing device 10 according to the present embodiment.
As shown in FIG. 1, the fixing device 10 includes a heating roll (rotating member) 11 positioned on the upstream side in the conveyance direction of the paper (recording sheet) P and a peeling roll (peeling member) positioned on the downstream side in the paper conveyance direction. , Peeling portion) 12, the heating roll 11, the fixing belt 13 wound around the peeling roll 12, and a space surrounded by the fixing belt 13 (on the inner peripheral surface side of the fixing belt 13) and the heating roll 11. A cooling device (first cooling unit, first cooling device) 14 positioned between the heating roll 11 and a pressure belt (pressure member) 15 disposed opposite to the heating roll 11, A main part is constituted by a pressure pad (pressing part, pressure member, hard pad) 16 located on the inner peripheral surface of the pressure belt 15 and pressed from the heating roll 11 via the pressure belt 15. The heating roll 11, the fixing belt 13, the pressure belt 15, and the pressure pad 16 constitute a melt pressure bonding part. The cooling device 14, a sheet guide (second cooling unit, second cooling device) 23 described later, and a blower unit (exhaust heat unit) 41 (see FIG. 3) described later constitute a cooling unit.

  The heating roll 11 is a cylindrical roll that is rotatably supported and rotates at a predetermined surface speed. Inside the heating roll 11, for example, a halogen heater 17 having a rating of 600 W is disposed as a heat source. The toner image formed on the paper P is heated by the heat of the halogen heater 17. On the other hand, a temperature sensor 18 is disposed in contact with the surface of the peeling roll 12. The temperature sensor 18 is for detecting the surface temperature of the peeling roll 12.

  The peeling roll 12 is a roll for urging the sheet (fixed object) P conveyed while being in contact with the fixing belt 13 by stretching the fixing belt 13 with a predetermined curvature. It is. The peeling roll 12 is formed in the cylindrical member with metal materials, such as aluminum and SUS (stainless steel), for example. The peeling roll 12 is rotatably supported by a support frame (not shown) and is elastically biased in a direction in which tension is applied to the fixing belt 13 by a known tension applying mechanism including a spring or the like. Yes.

The fixing belt 13 includes a belt base material having a thickness of about 30 to 200 μm and a seamless release layer formed on the outer peripheral surface side of the belt base material and having a thickness of about 10 to 200 μm. It is an endless belt. The belt substrate is formed using a heat-resistant resin such as polyimide or polyamide, or a metal material such as nickel or aluminum. The elastic release layer is formed of silicone rubber, fluorine rubber, or the like.
The outer peripheral surface of the fixing belt 13 (specifically, the surface of the elastic release layer) is preferably as smooth as possible (as close to a mirror surface) as possible. The fixing belt 13 is stretched between the heating roll 11 and the peeling roll 12 and rotates by the rotation of the heating roll 11.

More specifically, the paper guide 23 is disposed so that the fixing belt 13 faces the heating roll 11 and the peeling roll 12. That is, the paper guide 23 is located on the outer peripheral surface side of the fixing belt 13. The sheet P conveyed in close contact with the fixing belt 13 advances between the fixing belt 13 and the sheet guide 23 while being guided by the sheet guide 23. The paper guide 23 has an internal space 23a through which the air from the air blowing unit 41 (see FIG. 3) passes. Further, the paper guide 23 has a guide surface 23b that guides the paper P in contact with the paper P.
In addition, a temperature sensor 25 is disposed in the vicinity of the portion of the fixing belt 13 wound around the heating roll 11. The temperature sensor 25 is for detecting the surface temperature of the fixing belt 13.

  The cooling device 14 forcibly cools the belt inner peripheral surface portion of the fixing belt 13 from the heating roll 11 to the peeling roll 12, and a plurality of fins 14 a located on the heat radiating side include fixing belts. 13 is formed to extend in the width direction.

The pressure belt 15 is an endless belt without a seam. The pressure pad 16 disposed inside the pressure belt 15, the guide member 19, and further, not illustrated disposed at both ends of the pressure belt 15. It is rotatably supported by a belt regulating member. The pressure belt 15 is disposed so as to be pressed against the heating roll 11 at the nip portion N, and rotates following the fixing belt 13. In other words, the pressure belt 15 is wound around the heating roll 11 via the fixing belt 13, and a nip portion N through which the paper P passes is formed between the fixing belt 13 and the pressure belt 15.
Here, the pressure belt 15 is supported by the pressure pad 16 and the guide member 19 in a region excluding both ends in the width direction of the pressure belt 15. And in the area | region except the both ends of the pressure belt 15, the sliding holding sheet (low friction sheet) 20 arrange | positioned so that the internal peripheral surface of the pressure belt 15 may cover the pressure pad 16 and the guide member 19; It rotates while rubbing against the guide member 19.

  The pressure pad 16 is supported by the guide member 19 inside the pressure belt 15. Then, it is arranged in a state of being pressed against the heating roll 11 via the pressure belt 15 and forms a nip portion N with the fixing belt 13. In the pressure pad 16, a soft pad (pressing portion, pressure member) 21 for securing a wide nip portion N is disposed on the inlet side (upstream side) of the nip portion N. Further, the pressure pad 16 locally presses the surface of the heating roll 11 on the outlet side (downstream side) of the nip portion N, thereby smoothing the toner image surface and imparting image gloss.

  The pressure pad 16 has a sliding holding sheet as an example of a rubbing member on a surface in contact with the pressure belt 15 in order to reduce sliding resistance between the inner peripheral surface of the pressure belt 15 and the pressure pad 16. 20 is provided. The sliding holding sheet 20 is disposed in a state of being sandwiched between the pressure pad 16 and the inner peripheral surface of the pressure belt 15 in the entire nip portion N.

  The guide member 19 is provided with a lubricant-impregnated member (oil-impregnated felt) 22 along the longitudinal direction of the fixing device 10. The lubricant impregnated member 22 is disposed so as to be in contact with the inner peripheral surface of the pressure belt 15 and supplies an appropriate amount of lubricant. Thereby, the lubricant is supplied to the sliding portion between the pressure belt 15 and the sliding holding sheet 20, and the sliding resistance between the pressing belt 15 and the pressure pad 16 via the sliding holding sheet 20 is further reduced. Thus, the pressure belt 15 is smoothly rotated. In addition, there is an effect of suppressing wear on the inner peripheral surface of the pressure belt 15 and the surface of the sliding holding sheet 20.

  Between the heating roll 11 and the cooling device 14, a heat insulating member (a limiting part, a limiting member) 24 extending along the outer peripheral surface of the heating roll 11 is disposed. The heat insulating member 24 is disposed so as to partition the heating roll 11 and the cooling device 14. For this reason, the heat insulation member 24 insulates between both so that the heat of the heating roll 11 may not be transmitted to the cooling device 14. Further, the heat insulating member 24 prevents the wind passing through the fins 14 a from hitting the heating roll 11. The heat insulating member 24 is attached to a frame (not shown). In the present embodiment, the heat insulating member 24 is disposed between the heating roll 11 and the cooling device 14, but it is also conceivable to dispose the heat insulating member 24 between the pressure belt 15 and the paper guide 23. Further, depending on the layout of the constituent members, it is conceivable to arrange the heat insulating member 24 only between the pressure belt 15 and the paper guide 23.

  Further, the fixing device 10 includes cover members 26 and 27 that are positioned extending in the width direction (perpendicular to the paper surface) of the fixing belt 13 and are attached to the cooling device 14 and the heat insulating member 24. That is, the cover member 26 is attached to the upper end portion of the cooling device 14 near the peeling roll 12 and the upper end portion of the heat insulating member 24. Further, the cover member 27 is attached to the lower end portion of the cooling device 14 near the heating roll 11 and the lower end portion of the heat insulating member 24. The cooling device 14, the heat insulating member 24, and the cover members 26 and 27 constitute a duct portion 28 that is open at both ends, through which air guided to the air blowing portion 41 (see FIG. 3) passes.

  FIG. 2 is a schematic cross-sectional view for explaining the paper P. As shown in FIG. 2, the paper P is formed by laminating a transparent resin P2 mainly composed of a thermoplastic resin on a base material P1. Examples of the base material P1 include plain paper for image formation, coated paper, and photographic paper. Examples of the thermoplastic resin constituting the layer of the transparent resin P2 include a polyethylene resin and a styrene-acrylate resin. Further, the layer of the transparent resin P2 preferably has a layer thickness that is melted by heat and pressure at the time of fixing to embed the toner image. The sheet P is not particularly limited as long as it is a recording medium that can be applied to the image forming apparatus. From the viewpoint of obtaining a glossy photographic image by the fixing apparatus 10, FIG. It is preferable to use paper P.

FIG. 3 is a schematic configuration diagram for explaining air blowing in the fixing device 10.
As shown in FIG. 3, the fixing device 10 includes a blower unit (heat exhaust unit, fan) 41. Further, the fixing device 10 connects the duct portion 28 (see FIG. 1) of the cooling device 14 and the air blowing portion 41, and connects the internal space 23 a (see FIG. 1) of the paper guide 23 and the air blowing portion 41. A connecting portion 42 is provided.
The air in the duct portion 28 (see FIG. 1) and the air in the internal space 23a (see FIG. 1) of the paper guide 23 are discharged to the outside of the fixing device 10 by the blower portion 41 through the connection portion 42. As the air is discharged, the heat of the cooling device 14 constituting a part of the duct portion 28 is exhausted to the outside of the fixing device 10, and the heat of the paper guide 23 is exhausted to the outside of the fixing device 10. In this way, the single air blower 41 cools the fin 14a of the cooling device 14 by removing heat and also cools the paper guide 23.

FIG. 4 is a block diagram for explaining the control in the control unit 30.
As shown in FIG. 4, the temperature sensor 18 is disposed on the surface of the peeling roll 12 (see FIG. 1), and outputs the detected temperature to the control unit 30. The temperature sensor 25 is disposed in the vicinity of the fixing belt 13 and outputs the detected temperature to the control unit 30. Then, the control unit 30 controls the halogen heater 17 and the air blowing unit 41 according to the detection results from the temperature sensors 18 and 25. That is, the control unit 30 controls the blower unit 41 so that the temperature of the peeling roll 12 (see FIG. 1) maintains a set temperature (for example, 40 ° C.) based on the temperature measurement value by the temperature sensor 18. By such control of the air blowing unit 41, the temperature of the cooling device 14 and the paper guide 23 is maintained at the set temperature, and the temperature of the paper P being conveyed by the fixing belt 13 (see FIG. 1) is maintained at the set temperature. Is done.
Further, the control unit 30 controls the lighting of the halogen heater 17 based on the temperature measured by the temperature sensor 25 so that the surface temperature of the fixing belt 13 (see FIG. 1) maintains a set temperature (for example, 175 ° C.).

  Next, the operation of the fixing device 10 will be described. When the fixing operation time comes, the heating roll 11 shown in FIG. 1 starts to rotate so that the fixing belt 13 rotates, and under the control of the control unit 30, the halogen heater 17 generates heat by energization and causes the heating roll 11 to move. Heat to a predetermined fixing temperature and hold. At this time, the pressure belt 15 is driven to rotate by the rotation of the heating roll 11 via the fixing belt 13. Further, the air blowing unit 41 for cooling the cooling device 14 and the air blowing unit 41 for cooling the paper guide 23 start to operate before the fixing operation is started under the control of the control unit 30. Thus, the nip portion N is heated to a predetermined fixing temperature, and the fixing belt 13 is forcibly cooled by the cooling device 14 and the paper guide 23.

  Thereafter, the sheet P on which the toner image formed according to the image information on the image forming apparatus side is transferred to the fixing device 10 is sent to the nip portion N via a fixing inlet guide (not shown). Then, when the paper P passes through the nip portion N, the toner image on the paper P is melted by the pressure acting on the nip portion N and the heat supplied from the fixing belt 13 and embedded in the paper P. (Melt pressure bonding process). After passing through the nip portion N, the paper P on which the toner image has been fixed is conveyed along with the rotation of the fixing belt 13 while being in contact (contacted) with the outer peripheral surface of the fixing belt 13.

When the sheet P is conveyed while being in contact with the fixing belt 13, the sheet P is cooled from both the image surface and the non-image surface by the cooling device 14 and the sheet guide 23 (cooling process). That is, the heat held by the paper P that has passed through the nip portion N is transmitted to the fixing belt 13 that is cooled by the cooling device 14, and is also transmitted to the paper guide 23. And since the cooling device 14 and the paper guide 23 are cooled by the ventilation of the ventilation part 41, the heat transmitted to the cooling device 14 and the paper guide 23 is radiated. In other words, the heat in the area between the fixing belt 13 through which the paper P passes and the paper guide 23 is transmitted to the paper guide 23 and radiated.
Further, the heat of the heating roll 11 is prevented from being transmitted to the cooling device 14 by the heat insulating member 24 positioned between the heating roll 11 and the cooling device 14. In this way, the toner image and the paper P are substantially solidified by being cooled in such a state that the toner image is embedded in the paper P.

  Then, the cooled paper P is conveyed to the peeling roll 12 in contact with the fixing belt 13, the rotational state having the curvature of the fixing belt 13 over the peeling roll 12, and the strength of the waist of the paper P itself. When these are opposite to each other, they are naturally peeled off from the fixing belt 13 laid on the peeling roll 12 (peeling step). Thereby, fixing is completed. Thereafter, the paper P peeled off from the fixing belt 13 is sent to a storage tray (not shown) by a discharge roll (not shown).

  When the fixing by the fixing device 10 is normally performed, the toner image is fixed in a state where the toner image is uniformly embedded in the paper P as a result of uniformly performing the cooling in the cooling region uniformly. Then, the fixing is performed so that the surface of the sheet P after the fixing becomes the smooth surface of the fixing belt 13 and the smoothness is excellent. In other words, the image on the paper P after the fixing is obtained as a high-quality image that has little glossy reflection of light due to surface irregularities, is rich in gloss, and approximates a photographic image.

Here, some modified examples of the present embodiment can be considered. Hereinafter, the modification is demonstrated.
FIG. 5 is a schematic configuration diagram for explaining air blowing in the fixing device 10 according to the modification.
In the configuration shown in FIG. 5, in addition to the air blowing part 41 and the connection part 42 described above, the air blowing part 43 </ b> A that blows air to the cooling device 14 and the paper guide 23, and the air blowing part 43 </ b> A, the cooling device 14, and the paper guide 23 are connected. 44A. That is, air is forcibly sent to the cooling device 14 and the paper guide 23 by the air blowing unit 43 </ b> A, and the air is forcibly discharged out of the fixing device 10 by the air blowing unit 41. The control of the blower 43A is performed by the controller 30.

FIG. 6 is a schematic configuration diagram for explaining air blowing in the fixing device 10 according to another modification.
In the configuration shown in FIG. 6, not only the cooling device 14 and the paper guide 23 but also the peeling roll 12 is connected to the connecting portion 42 described above. The peeling roll 12 has a cylindrical shape and is configured so that air can pass through the inside thereof. For this reason, the air inside the peeling roll 12 is discharged to the outside of the fixing device 10 by the blower 41 via the connecting portion 42, and accordingly, the heat received by the peeling roll 12 from the fixing belt 13 and the paper P is fixed. Heat is exhausted to the outside of the apparatus 10. In this modification, since the heat of the peeling roll 12 is exhausted by the blower 41, the paper P cooled by the cooling device 14 and the paper guide 23 is removed from the fixing belt 13 without being reheated by the peeling roll 12. Peel off.

FIG. 7 is a block diagram for explaining the configuration of the image forming apparatus 100 to which the fixing device 10 is applied.
The fixing device 10 according to the above-described embodiment can be applied to an image forming apparatus 100 using an electrophotographic system such as a copying machine, a printer, a facsimile machine, or a multifunction machine of these. 7 includes a toner image forming unit 110 that forms a toner image, a transfer unit 120 that transfers the toner image formed by the toner image forming unit 110 onto the paper P, and a transfer onto the paper P. The image forming apparatus includes a fixing unit 130 that fixes the toner image to the sheet, and a sheet supply unit 140 that supplies the sheet P to the transfer unit 120 at a predetermined timing. As the fixing unit 130, the above-described fixing device 10 according to the present embodiment can be used. Note that any configuration other than the fixing device 10 can be used as long as it is not contrary to the object of the present invention. The toner image forming unit 110 includes an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and a developing unit that develops the electrostatic latent image with toner. The

FIG. 3 is a side sectional view showing a configuration of a fixing device according to the present embodiment. It is a schematic sectional drawing for demonstrating a paper. FIG. 3 is a schematic configuration diagram for explaining air blowing in the fixing device. It is a block diagram for demonstrating the control in a control part. It is a schematic block diagram for demonstrating the ventilation in the fixing device which concerns on a modification. It is a schematic block diagram for demonstrating the ventilation in the fixing device which concerns on another modification. 1 is a block diagram for explaining a configuration of an image forming apparatus to which a fixing device is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fixing device, 11 ... Heating roll, 12 ... Peeling roll, 13 ... Fixing belt, 14 ... Cooling device, 14a ... Fin, 15 ... Pressure belt, 16 ... Pressure pad, 17 ... Halogen heater, 18, 25 ... Temperature Sensor, 19 ... Guide member, 20 ... Slide holding sheet, 21 ... Soft pad, 22 ... Lubricant impregnated member, 23 ... Paper guide, 23a ... Internal space, 24 ... Heat insulation member, 26, 27 ... Cover member, 28 ... Duct section, 30 ... control section, 41, 43A ... air blowing section, 42, 44A ... connection section, N ... nip section, P ... paper

Claims (9)

A nip portion is formed by a fixing belt to which heat is applied and a pressure member pressed to the fixing belt, and when the recording sheet passes through the nip portion, a toner image on the recording sheet is transferred to the heat of the fixing belt. A melt-bonded part that is melted and pressure-bonded to the recording sheet;
The toner image is melted and pressure-bonded by the melt pressure-bonding portion, which is located on the inner peripheral surface side of the fixing belt, and the recording sheet attached to the fixing belt is cooled while being attached to the fixing belt. 1 cooling section;
A second cooling unit that is located on the outer peripheral surface side of the fixing belt and cools the non-attachment side of the recording sheet attached to the fixing belt;
A peeling unit for peeling the recording sheet cooled by the first cooling unit and the second cooling unit from the fixing belt;
Including a fixing device.   It further includes a restricting portion that is disposed between the melt-bonding portion and the first cooling portion and / or the second cooling portion and restricts the transfer of heat from the melt-bonding portion to the cooling portion. The fixing device according to claim 1.   The fixing device according to claim 1, wherein the second cooling unit includes a guide surface of a recording sheet. An exhaust heat section for discharging heat of the first cooling section and the second cooling section to the outside of the apparatus;
A connection part for connecting the first cooling part and the second cooling part to the exhaust heat part;
The fixing device according to claim 1, further comprising: A heat source,
A fixing belt that receives supply of heat from the heat source;
A pressure member arranged to contact the fixing belt;
A pressure member for forming a nip portion through which a recording sheet is passed between the fixing belt and the pressure member;
A peeling member that is wound around the fixing belt and peels off the recording sheet attached to the fixing belt at the nip portion;
A first cooling device for cooling the image surface of the recording sheet adhering to the fixing belt;
A second cooling device for cooling the non-image surface of the recording sheet adhering to the fixing belt;
Including a fixing device.   The apparatus further includes a limiting unit that is disposed between the heat source and the first cooling device and / or the second cooling device, and restricts movement of heat from the heat source to the cooling device. Item 6. The fixing device according to Item 5. An exhaust heat section for discharging the heat of the first cooling device and the second cooling device to the outside of the fixing device;
A connecting portion for connecting the first cooling device and the second cooling device to the exhaust heat portion;
The fixing device according to claim 5, further comprising: An exhaust heat section for discharging heat of the first cooling device, the second cooling device and the peeling member to the outside of the fixing device;
A connecting portion for connecting the first cooling device, the second cooling device, and the peeling member to the exhaust heat portion;
The fixing device according to claim 7, further comprising: Toner image forming means for forming a toner image;
Transfer means for transferring the toner image formed by the toner image forming means onto a recording sheet;
Fixing means for fixing the toner image transferred on the recording sheet to the recording sheet;
Including
The fixing means is
A nip portion is formed by a fixing belt to which heat is applied and a pressure member pressed to the fixing belt, and when the recording sheet passes through the nip portion, a toner image on the recording sheet is transferred to the heat of the fixing belt. A melt-bonded part that is melted and pressure-bonded to the recording sheet;
The toner image is melted and pressure-bonded by the melt pressure-bonding portion, which is located on the inner peripheral surface side of the fixing belt, and the recording sheet attached to the fixing belt is cooled while being attached to the fixing belt. 1 cooling section;
A second cooling unit that is located on the outer peripheral surface side of the fixing belt and cools the non-attachment side of the recording sheet attached to the fixing belt;
A peeling unit for peeling the recording sheet cooled by the first cooling unit and the second cooling unit from the fixing belt;
An image forming apparatus comprising:

Images